3D Secure (3-domain structure), also known as a payer authentication, is a security protocol that helps to prevent fraud in online credit and debit card transactions. This security feature is supported by Visa and Mastercard and is branded as ‘Verified by Visa’ and ‘Mastercard SecureCode’ respectively.

For more information, see the 3D Secure Guide.

Figure 1-8: 3D Secure Transaction Flow